The 1939 Fisher-bodied Series 61 used a wheelbase. All GM vehicles for 1939 adopted the Torpedo appearance with an extended, protruding bow appearance to enhance its aerodynamic appearance. A number of modern ocean liners had been recently launched and the appearance was very popular at the time. 1939 was also the year of the 1939 New York World's Fair and the streamline appearance gave a futuristic look when it was on display at the Futurama exhibit. The protruding center grille and the functional side grilles were die-cast, with slender bars. Single die-cast louvers were positioned to the rear of each hood side panel for engine compartment ventilation.
It was available as a club coupe, convertible or sedan, and a manual retracting center divider made from safety glass was optional on the sedan, along with the choice to add or remove running boards. Sales of the Series 63 were 5,030 in 1941 and 1,750 in 1942 before production was suspended February 4, 1942 to contribute to the war effort.
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|related = Buick Special<br />Oldsmobile Series 70<br />Pontiac Streamliner
Model year 1942 saw a dramatic appearance change on all GM vehicles, where the curve of the front fenders extended halfway across the front doors, called "Airfoil" and fastback appearance was adopted company-wide. Vehicles that were built until February 1942 could be identified as lacking chrome trim starting in January when it was prohibited due to wartime production and trim pieces including bumpers were painted.<br />1950–51:
|length = 1948–49: There was also an attractive eggcrate grille, which was higher in the middle than on the sides. The front of the car was protected by a heavier and more massive bumper bar that curved around the fenders. The Cadillac crest was centered low in a "V" above the radiator grille. Chrome headlamp rims were used. Cars in the 61 series lacked bright metal front fender shields and under-taillight trim. A new dashboard with "rainbow" style instrument cluster and leather grained panels extending to the carpets was seen only this year.
The big news at Cadillac in 1949 centered on engineering, with the release of a new overhead valve V8 engine. This 331 in³ engine produced 160 hp (119 kW). Only minor appearance changes were seen. They included a more massive grille treatment with grooved extension panels housing the front parking lights and chevron slashes below the taillamps on the coupes. Once again the cars in this line lacked front fender gravel shields and rocker panel moldings and had plainer interior trim. A larger luggage compartment lid was seen on all sedans except early production units. Standard equipment now included twin back-up lamps mounted on the deck lid latch panel.
Cadillacs had extensive styling changes in 1950, as its appearance is similar to cross-town rival Chrysler Imperial and the Chrysler New Yorker initially in 1949, and less so with yearly appearance changes. They looked generally heavier and had low sleek contours with longer rear decks, more sweeping front fenders and a broken rear fender line. The hood protruded more at front and was underlined by a more massive eggcrate grille. Round parking lights were used, but as in the past, when buyers chose fog lamps an additional bulb and larger housing were used. This setup combined the fog lamps and the directional signals. One piece windshields were introduced and the leading edge of the rear fenders which had a broken-off look, was highlighted by chrome imitation air slots. The rear fenders were longer and ended in a swooping tailfin design. The Cadillac script again appeared on the sides of the front fenders, but was now positioned closer to the front door opening gap. As far as Series 61 models went a big styling change was a return to marketing this line on the shorter wheelbase B-body than used on the Series 62. This led to some styling differences. For example, the Series 61 Sedan had no rear window ventipanes and featured a rear wraparound backlight. An identifying feature on both models was the absence of rocker panel moldings and rear quarter panel chrome underscores. The Series 61 was 4 inches shorter than in the previous season.
A minor face lift and small trim variations were the main Cadillac styling news in 1951. Miniature eggcrate grilles were set into the outboard grille extension panels below the headlights. Larger, bullet shaped bumper guards were used. The features list included handbrake, warning lamp; key start ignition; steering column cover; Delco-Remy generator; knee-action front suspension; directionals; mechanical fuel pump; dual downdraft carburetor; slipper-type pistons; rubber engine mounts; oversize brakes; Super Cushion tires; one-piece windshield; intake silencer; 160-hp engine; oil bath air cleaner; equalized manifolding; automatic choke and luxury appointments. On the dashboard "idiot lights" were used to monitor oil pressure and electrical charge rate instead of gauges. The smaller body was once again used on the 61s and again identified by the lack of chrome underscores. However a new medallion appeared on the rear roof pillar of the Series 61, above the upper beltline molding.
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File:1950 Cadillac Series 51 (24560862545).jpg|1950 Cadillac Series 51 Sedan.jpg
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Racing
thumb|"Le Monstre" of the [[1950 24 Hours of Le Mans|1950 Le Mans 24h]]
Briggs Cunningham and his team brought 2 Series 61 DeVilles to the 1950 24 Hours of Le Mans. One of the cars, dubbed "Le Monstre", was modified for racing. The other, ‘’Petit Petaud (Small puppy)’’, was essentially stock with some minor modifications. The stock coupe finished 10th overall while the modified car finished 11th because Cunningham got stuck in the sand for 30 minutes.
Film use
A 1939 convertible Cadillac Series 61 was used in the Batman film serial of 1943 to represent the Batmobile.